NonStop NS-Series Database Migration Guide

Preparing to Migrate to an Integrity NonStop
NS-Series System
HP Integrity NonStop NS-Series Database Migration Guide—540469-001
1-10
Selecting Data Movement Tools
Phased (or side-by-side) migration involves careful and incremental replication of your
current production database to the Integrity NonStop NS-series platform. While the
NonStop S-series production system continues to operate as the primary database,
preselected portions of the database are copied in phases over an Expand network to
a new Integrity NonStop NS-series system. After all data has been successfully copied
to the NonStop NS-series system and thoroughly tested and validated, that system
becomes the primary database.
Rapid migration involves relatively fast and difficult-to-reverse migration of the
database on a NonStop S-series production system directly to an Integrity NonStop
NS-series production system. For example, migrating a database by physically
disconnecting and reconnecting disk storage devices is a rapid migration. For an
example of rapid migration, see Migration by Online Database Replication on page 2-2.
Table 1-5 describes the criteria you might use to choose between phased migration
and rapid migration. Given a choice between these two strategies, a customer who has
a large, complex database, for whom uninterrupted business continuity and risk
avoidance are very important, and for whom a longer migration timeframe is
acceptable, would probably choose phased migration. A customer who has a smaller,
simpler database, for whom quick migration is important, and for whom some
short-term downtime is acceptable, would probably choose rapid migration.
Selecting Data Movement Tools
After you define your database migration strategy, select the data movement tool or
tools that are most appropriate for your needs. Table 1-6 shows these tools and their
usefulness with respect to important database migration criteria.
Table 1-5. Choosing Phased Migration or Rapid Migration
Migration Approach
Large, complex database Small, simple database Availability is very important Availability is less important Small migration window Larger migration window High risk aversion Leverage existing I/O devices
Phased migration X X X X
Rapid migration, such as a hardware move X X X X